/Engine/Source/Runtime/SlateCore/Public/Rendering/SlateRenderer.h
Queues a dynamic brush for removal when it is safe. The brush is not immediately released but you should consider the brush destroyed and no longer usable
void RemoveDynamicBrushResource ( [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [FSlateDynamicImageBrush](API\Runtime\SlateCore\Brushes\FSlateDynamicImageBrush) > BrushToRemove )